A bit of clarification on Node placement in regards to why some star systems have them while others don't would be nice.  For instance I had a similar system myself that had stellar mass correlations (as the nodes were general by mutual gravitational tugging, which means that larger stars linked to each other while ignoring smaller stars and in general a convoluted web existed, I actually worked on a near sol setting myself and still have the link map for it, issue is that it's so horrifyingly convoluted it has no practical use.)  Chances are it may be better to only highlight the high traffic/major nodes in regards to the map.  Astrosynthesis has add-ons that add thousands of real star systems up to 300 Ly from sol with some level of accuracy. ([url=http://www.atlasoftheuniverse.com/250lys.html]That is still like, a lot of star systems[/url])   I am not certain how distant human expansion is but my intuition is that there may be colonies situated around the Hyades star cluster, but most likely not to the Pleiades which may still be a unknown and may house a drone hive from a dead civilization for all anyone knows.  "Here be dragons"?  Here be aliens.